hw.module @no_outputs(%I: i1) -> () {
    %1 = hw.constant -1 : i1
    %0 = comb.xor %1, %I : i1
}
hw.module @simple_side_effect_instance(%I: i1) -> (O: i1) {
    hw.instance "no_outputs_inst0" @no_outputs(I: %I: i1) -> ()
    hw.output %I : i1
}
